Sewing machine needle control mechanism



1954 w. R. BLIEDUNG ETAL SEWING MACHINE NEEDLE CONTROL MECHANISM 2Sheets-Sheet 1 Filed Aug. 16 1950 ii W [0% GINVENTORJ mmwmw Oct. 26,1954 w. R. BLIEDUNG ETAL 2,592,667

SEWING MACHINE NEEDLE CONTROL MECHANISM Filed Aug. 16, 1950 2Sheets-Sheet 2 a /(E Call- H 45 lees/57oz Patented Oct. 26, 1954 SEWINGMACHINE NEEDLE CONTROL MECHANISM Walter R. Bliedung and Herman C.Frentzel, Milwaukee, Wis., assignors to Hansen Glove Corporation,Wisconsin Milwaukee, Wis., a corporation of Application August 16, 1950,Serial No. 179,866

3 Claims. 1

This invention relates to improvements in sewing machine needle controlmechanisms.

Although the invention is susceptible of wider applications, and is notto be restricted, the present improvements find particular utility inconnection with the operation of an electric powered sewing machinewhich may be operated to apply circuitous seams along the marginalportions of shaped fabric or leather pieces, as for the production ofgloves. In this particular field, as well as in others of an analogousnature, in order to maintain proper production requirements, it isdesirable for the machine operator to be able to control the sewingmachine instantaneously and without due efiort or thought, and to alsobe able to control the position of the needle or tool with respect tothe material being worked on,

Along certain portions of the fabric or leather being worked on, thesewing machine may be run at high speed, but when other portions of thefabric are reached, in order to permit the operator to turn the fabricand to sew carefully around curved or eccentric marginal portions of thematerial, it is highly desirable that the machine be stoppedinstantaneously and then be susceptible of a slow stitch by stitchoperation. The machine should also be susceptible of operation so as tohave the needle stop in the fabric to permit the fabric being pivotedaround the down engaged needle, or, there may be a high speed operation,according to the requirements, when the fabric is rearranged. Thecontrol of the sewing machine should be accomplished with a minimum ofattention on the part of the operator in order that he may devote histime to the correct feeding and positioning of the work, leaving bothhands free for engaging the fabric.

With the present improved mechanism, therefore, not only can theoperator control his machine stitches without taking his hands from thematerial being worked on, but the improved control mechanism alsoprovides means whereby the operator may automatically position theneedle, between sewing operations, so that the material can be properlypositioned for the next high speed power sewing, it being noted thatformerly it was necessary for the operator at such stages to manuallyturn the hand-wheel of the sewing machine in order to properly positionthe needle.

As an example, in the closing operation of a glove there are normallytwenty-six stops and starts in the sewing operation. With conventionalmechanisms the operator was required to set the hand-wheel during eachof these stops for the purpose of positioning the needle and work.

With respect to the enumerated stops it is desirable to haveapproximately twenty-four of the stops with the needle in the material,while the balance of the stops require that the needle be out of thematerial. The present invention, in addition to the purposes recited,provides means for automatically stopping the needle in a desired in orout position, thereby saving the tedious hand manipulation of the sewingmachine handwheel, speeding up operations, and reducing the fatigue towhich the operator may be subjected.

With the above general explanation in mind, it is, therefore, a primaryobject of the present invention to provide a sewing machine needlecontrol mechanism whereby the speed of operation of the needle or othermotor operated tool may be changed from high speed operation to zerospeed, and vice versa, and whereby the needle will always be stoppedeither in or out of the work, according to the desire of the operator.

A further object of the invention is to provide a sewing machine needlecontrol mechanism wherein the position of the needle, either in or outof the work, is selectively accomplished instantaneously and positivelyand with little effort and thought on the part of the operator.

A further object of th invention is to provide a sewing machine needlecontrol mechanism which will permit on and ofi operation of the machine,which will insure stoppage of the machine with the needle either in orout of the work according to a predetermined plan, and which willfurthermore effect decontrol to permit free wheeling of the mechanism ifthat is desired for any operations, as for threading the needle.

A further object of the invention is to provide a sewing machine needlecontrol mechanism which may be readily built into or associated with astandard electric sewing machine, which is adapted to commercial andlarge scale operations to maintain high production requirements, whichis automatic in its operation, which is strong and durable, and which iswell adapted for the purposes described.

In the accompanying drawings in which the same reference charactersindicate the same parts in all of the views:

Fig. l is a fragmentary detail sectional view of a sewing machine headwherein the needle reciprocating mechanism has associated therewith andis under the control of a centrifugal switch mechanism, shown insection, with the assemblage also including a solenoid actuated clutchand brake electro transmitter (shown in section) furnishing power to thesewing machine flywheel, said view also including a schematic view ofthe control treadles and the wiring arrangement;

Fig. 2 is a sectional View taken on line 2-2 of Fig. 1;

Fig. 3 is a sectional View taken on line 3-3 of Fig. 1 and on a largerscale;

Fig. 4 is a sectional view taken on line 5-4 of Fig. 1 and on a largerscale; and

Fig. 5 is a detailed wiring diagram.

The present invention, although not restricted thereto, finds particularutility in connection with the operation of a motor driven sewingmachine, such as is used in the commercial production of fabric, leatheror specific articles, especially for the manufacture of gloves.

The machine tool, which in this instance is a reciprocating sewingmachine needle, through the improved control mechanism is susceptible ofinstantaneous on and off operation and, additionally, according to anypredetermined plan, the machine may be stopped with the needle either inor out with respect to the material being worked on.

To further understand the utility of the present invention in connectionwith the operation of a powered sewing machine, it should be understoodthat a normally powered sewing machine is controlled by the operatorthrough the means of a foot treadle, and the latter, through differentdegrees of movement, effects cessation of the operation of the machine,or operation of the machine at various speeds. In the conventionalarrangements the operator must constantly work on the control treadle,which becomes very fatiguing and additionally requires varying degreesof pressure and motion and attention on the part of the operator. Inconnection with conventional operations it is also a fact that there isa considerable time lag between operations because of the necessity ofawaiting the machine actuating elements to actually take hold or effect.Consequently, in conventional electric sewing machines many types ofwork, and parts of the sewing, require the operator to manuallymanipulate the sewing machine hand-wheel to perform stitch by stitchoperations and to cause the needle to be either in or out of the work sothat the material can be positioned or turned for the next power sewing.With the present improvements the cited difficulties are entirelyeliminated and on and ofi of the power sewing mechanism is accomplishedby an unmeditated feather touch on the control pedal without appreciabletime lag, and additionally, the mechanism can always be stopped with theneedle either in or out, according to what is desired.

In the present invention, one unit of the improved control mechanismcomprises an electrically controlled solenoid operated transmitter,generally indicated by the numeral l5 and directly associated orincorporated with an electric motor 56. The transmitter l5 and motor l6are preferably in the form of a unit and carry upwardly directedbrackets I'I merging into a horizontal plate [8 whereby the unit may bebolted or otherwise secured to the table portion IQ of an electricsewing machine 20.

The outwardly extending shaft of the electric motor is is designated bythe numeral 2| and the central hub portion of a flywheel 22 is keyed tothe enlarged inner end portion of said motor shaft 2!. The outer end ofthe motor shaft is reduced and carries fast thereon a circular drivingsolenoid 23 whose flanged inner end portion is rigidly attached to theflywheel 22 by screws 24. A clamping stud or screw 25 extends centrallyaxially into the solenoid 23 to abut the outer end of the motor shaftportion thereadjacent. Carried fast by the outer peripheral portion ofthe solenoid 23 is a running clutch 2% of annular formation. Set intothe opposite faces of a metallic plate 40 and of magnetic material, arerings of any suitable clutch fabric or friction material 28. In theouter face of the flywheel 22, against a ring of insulating material 29there is secured a copper ring 3%. Said copper ring is electricallyconnected to the windings 3! of the solenoid 23 by means of wiring.Current is conducted to the copper ring as by a brush 33 mounted on theinner end of an adjustable stem 3 1 which is threaded through a lowerframe arm 35, being maintained in its adjusted position by a clampingnut 36.

The frame portions H and 35 are shaped to form a separable circularbearing enclosing the sleeve portion 37' of a brake solenoid 3?. Withinthe sleeve portion 3'! there are roller bearings 38 to facilitateturning movement of a pulley shaft 39 which extends axially through thesleeve portion 3i" and through the central portion of the solenoid 31.The innermost end portion of the pulley shaft 39 has splined thereto thehub of the metallic plate til, previously mentioned. The outermost endportion of the shaft 39 has fast thereon a pulley M which drivinglycarries a belt it. A ring-like brake clutch 42 of split formation, andsimilar to the clutch 26, is in screw threaded engagement with the outerperiphery of the solenoid 31. Electrical current is conducted to thewindings 43 of the solenoid 3'? by a suitable circuit wire M1, and itmay also be stated that the brush 33 carries a circuit wire :35. Circuitwire A5 is connected directly with a terminal on a suitable treadleswitch it which is shown schematically in Fig. 1 and circuit asultimately connects with the other terminal on said treadle switch. Inpractice, this treadle switch is manipulated by the foot of the machineoperator and controls instantaneous off and on or running and stoppingof the machine mechanism associated with the improved solenoid operatedtransmitter.

From the description thus far given it should be evident that the shafts2! and 39 are separated and that the former has fast thereon thesolenoid 23, while the pulley shaft 39 is free to turn within the hubportion of the solenoid 3?, which is stationary. However, the metallicplate id is splined to the inner end of the pulley shaft 39 so as to beselectively engageable with either the face portion of the solenoid 23or the face portion of the solenoid 3'8, depending upon which isenergized. Consequently, the splined mounting of the disc 40 is suchthat the disc may have minute axial movement on the shaft 39 for thepurpose of being pulled against which ever solenoid is energized.

The sewing machine 26 to be associated with and controlled by theimproved solenoid operated transmitter has a driving sheave or pulley Hto which the belt H3 extends. The sewing machine is of the type whichshould operate, when, on at high speed, and then be susceptible ofimmediate cessation, under the control of the operator with the sewingmachine needle either in or out of the work, according to whatever isdesired. It will, therefore, be appreciated that for on and offoperation of the sewing machine, by means of the transmitter 15, if theoperator imparts pressure to the treadle sufficient to close the contactelement of the switch 46 with the terminal which carries the circuitwire 45, the solenoid 23, through the coil 3|, will be energized andwill magnetically attract to its face the metallic plate 40, the latterbeing disengaged from the solenoid 37, because under these conditions,the last-mentioned solenoid is deenergized. Engagement between therevolving solenoid 23 which is driven directly from the electric motorl6, and the me tallic plate is effective to rapidly revolve the pulleyshaft 39 and through the belt 1 l motion is transmitted to the pulley ll of the Sewing machine.

When it is desired to stop or brake the sewing machine the operator thenmanipulates the treadle switch in a manner to open the circuit throughthe wire 45 and to make the circuit through the wire 44, therebyenergizing the solenoid 31 and deenergizing the solenoid 23. The resultis that the metallic plate 40 is immediately engaged with the solenoid3'! and rotation is instantly arrested through the braking material onthe adjacent face of the plate 40.

The electric motor 16 carries conventional circuit wires 48 which may beextended to the source of electrical current and it should be observedthat a circuit wire d9 connects with one of the terminals of a decontrolswitch 1%, later to be described, which also extends to the power supplythrough a rectifier 10!. The same is true of a circuit wire 8 which hasits inner end grounded on a metallic frame portion of the transmitter[51, as at 42.

While an electric motor I 6 has been illustrated in association with thetransmitter l5, it'should be understood that the shaft 2! may be drivenfrom any convenient power source.

Another unit of the improved control mechanism comprises a centrifugalswitch device shown in section in Fig. l and indicated generally by thenumeral 56. This centrifugal switch assembly is supported by anupstanding bracket arm 5i whose base portion is bolted or otherwisesecured to the top surface of the sewing machine table portion [9. Itwill be observed that the sewin machine pulley H is formed on its outerface with a dished extension H which receives a disc 52 which is securedto the pulley l I by bolts 53 so as to turn therewith.

The disc 52 has an outwardly projecting axial hub portion 54 andradially outwardly of said hub portion the disc carries protuberances 55on which are pivotally mounted governor weights 56.

It was previously noted that the sewing machine pulley wheel II ispositively driven by the belt Iii. As the pulley H accelerates in speedthe governor weights 56 pivotally move, by centrifugal force, in adirection so that the fingers 55, formed on the inner ends of thegovernor weights, move toward the left (relative to Fig. 1) and therebyimpinge against the inner annular shoulder on a sleeve 51, which axiallysurrounds the hub portion 54 of the disc 52. Confined within ashouldered recess therefor in the sleeve 5'! is a coiled spring 58 andthe action of the governor weights described and the axial movement ofthe sleeve 5'! compresses said spring 58 causing a disc cam is to moveaxially toward the left relative to Fig. 1 and away from switch plungerswhich are loosely mounted through bores therefor in a stationary guideblock 6!. It should be observed that the disc cam 59 has a sleeveportion slidably embracing the hub portion 54 of the disc 52 inwardly ofthe sleeve 51. Enough axial movement is afforded the disc cam 59 and itssleeve so that the disc cam will not contact the ends of the switchplungers 60 during running operation, thus preventing wear on both thecam and on the plungers, and permitting the switch plungers til to be inreleased position and thereby holding switches 62 and 62' in circuitbreaking position when switch 46 is released or in its stop position.

In the specific embodiment illustrated, the machine whose tool is to becontrolled, is the power operated sewing machine 20 having a needle 63depended from a vertical reciprocatory needle shaft 64. The latter, asis conventional, carries a block engaged by a cam 86 on the inner end ofa revoluble shaft 61, the latter carrying fast at its other end thesewing machine drive pulley H which, as was previously mentioned, isengaged by the driven belt l0. Not only does the sewing machine needlecontrol mechanism provide means for instantaneously stopping or startingthe reciprocations of the needle 63, but the unit 50 provides positivemeans for insuring the stoppage of the needle 63 either in its downposition with respect to the work on the table I!) being sewed, or in anup, out-of-the-work posi tion. The latter are the functions of theswitches 62 and 62 whose wiring arrangement in the system will beapparent from Figs. 1 and 5. According to the particular circuitarrangement, the switch 82, for instance, controls the needlein stoppageof the machine, and the switch 62 controls the needle-out position ofstoppage.

With particular reference to the schematic portion of Fig. 1, whereinthe treadle switch 46 is shown which is adapted to be engaged by thefoot of the machine operator, if this treadle switch which controls therunning and stopping of the machine is released, the circuit to theclutch solenoid 3| is opened and the circuit to the magnetic brakesolenoid 43 is closed through circuit wires 44, the normally closedcontacts of switch 62 or 62, wires 44 or 44 (depending on the conditionof switch 62 or 62), and then to the proper terminal of switch 58. Then,the driving disk 40 of the unit I5 is removed from contact with theclutch member 26 and is firmly engaged with the magnetic brake element42. The operation of the brake causes rapid deceleration of the drivenpulley H on the sewing machine shaft 6?, which, upon coming to rest,permits the governor spring 58 to thrust the disc cam 59 of theassemblage 53 in an axial direction against the face of the block 6|.Should the driven pulley ll stop rotation in a pre-selected position,the machine remains inoperative until either the run-stop treadle switch46 or a needle up-or-down switch 68 is operated.

As was previously brought out it is, of course, a specific object of theinvention to provide means for positively determining the position ofthe sewing machine needle 63 (either in or out of the work) according toa predetermined selection, when the machine stops. This is the functionof the switches 62 and 62 controlled by the governor operated cam disc59. It is possible that the normal momentum of the machinery might, whenthe sewing machine stopped, cause the needle to be out of the work, forinstance, although the operator desired the needle to stop in its down,in the work position. The switch plungers 60 are loosely mounted throughthe guide block El and the upper plunger 6?] operates switch 62 whilethe lower plunger 60 operates switch 62'. If the disc cam 59 is forcedtoward the right in Fig. 1 and is in the position shown in Figs. 1 and 4it will, of course, actuate the upper switch plunger 69 for the switch62 thereby deenergizing the brake solenoid Q3 and energizing the clutchsolenoid 3!. This causes rotation of the pulley ll under two conditions.Should the cam 59 be in such a position that the upper plunger 69, forinstance, of switch 62 is about to be disengaged by said cam, then assoon as this occurs there is an energization of the brake solenoid 43and a deenergization of the clutch solenoid 31. This satisfies thecondition imposed by the predetermined position of the needle up or downtreadle 88. On the other hand, should the advance portion of the cam 59just have engaged and depressed the upper plunger 68, then the clutchsolenoid 3! will be energized and the hub 54 again rotates with cam 59until the speed of the pulley II is of such magnitude as to move thecentrifugal weights 55 to shift the cam 59 to the left. At this pointthe brake solenoid 43 is again energized, causing deceleration of themachine, so as to stop the needle We in the desired position. Thepurpose of the centrifugally controlled switches 62 and 82 is to preventan override of the position desired, as the solid cam face 59 is, attimes, a large percentage of the complete periphery.

If the switch 68 is actuated rapidly the operator of the machine maytake a power driven single stitch. or inching operation for eachcomplete up and down manipulation of said treadle switch 68. Withreference to the schematic portion of Fig. 1 and also with reference toFig. 5, the switch It!) is a free wheeling treadle switch which opensthe circuits to both the clutch and brake solenoids, thereby allowingthe machine to be indexed by hand for needle threading or otherpurposes.

The operation of the improved mechanism is as follows:

With the electric motor 16 in operation, initially all of the switchesin the system except the run-stop switch 45 are in normal releasedpositions. The brake solenoid 43 is energized through the circuit fromthe source or rectifier it! through contacts C-NC (Fig. of the run-stoptreadle switch 46 and then through contacts C-NC of the needle up anddown treadle switch 58, and finally through contacts C-NC of the controlswitch 62 and through the circuit wires M or M" and then wire 44 to thebrake solenoid 43.

A foot manipulation of the run-stop treadle switch 46 energizes theclutch solenoid 3! from the rectifier or source, through contacts C-NOof the run-stop treadle switch at (Fig. 5) and circuit wire 45. As themachine accelerates, both control switches 62 and 52' close their C-NCcontacts. The release of the run-stop treadle switch as functions toclose contacts C-NC thereof whereby an energization of the brakesolenoid 43 takes place through either the control switch '62 or thecontrol switch 52, depending upon the particular position of the ne dleup or down treadle switch 68 and circuit wire 44. When the machine comesto a stop, the axial motion of the disc cam 59 functions to close eitherthe switch 62 or the switch 62. If the machine stops in a position whichwould have the needle in an undesired position according to the work,the circuit to the brake solenoid d3 is then interrupted by either ofthe control switches 60 or 62 through circuit 34 and there is atemporary energization of the clutch solenoid 3| until such time as thedesired position is reached for the stopping of the needle (either up ordown, as pre-selected) By particular reference to Fig. 5 and alsoreferring to the schematic portion of Fig. 1, it should be evident thatthe electrical system includes a pair of inter-related electricalcircuits. One circuit, which may be termed the control or non-runningcircuit includes and is under the control of the main stop and runswitch it, and additionally includes the needle up and needle downswitches 62 and 62. The other circuit which is inter-related with thefirst mentioned circuit may be termed a running circuit and besides themain switch We also therein, said running circuit includes the clutchand brake solenoids 3i and t3. Said running circuit is, of course,affected by the first mentioned control circuit when it is necessary forthe machine to readjust itself for a predetermined selected needleposition, when the machine stops, as previously described.

From the foregoing it should be evident that the unit 50 associated witha machine such as a sewing machine, which also has incorporatedtherewith the electircally controlled solenoid operated transmitter !5,makes it possible, through selected operation of the needle up or downtreadle, to have the machine positively stop with the needle in apredetermined up or down position. These results are obtained from thegovernor weights 56 which are effective to axially move the sleeveportion of the cam disc 5% whereby, during operation, said sequence camdisc 59 is moved away from the switch plungers, whereby the brakecircuit is immediately completed when the machine operator lifts hisfoot from the run-stop treadle switch 46. A mechanism such as a powersewing machine equipped with the improved control mechanism can beoperated with a minimum of attention on the part of the operator leavinghis hands free for feeding and positioning the work. The controlmechanism also has the other advantageous functions heretofore mentionedincluding free-wheeling and the change in the speed of operation of thetool from. high speed to zero speed, and vice versa.

The improved sewing machine needle control mechanism is furthermore ofrelatively simple construction and is well adapted for the purposes setforth.

What is claimed as the invention is:

1. A control apparatus for an automatic tool, comprising a driven shaftconnected to said tool for operating the latter, a solenoid operatedstop and go transmitter operatively connected to said shaft to drive it,and means for predetermining either of two separated positions of restof said tool upon cessation of operation of the transmit ter, saidlatter means including first and second tool rest position controlswitch members electrically associated with said transmitter, manuallyoperated means electrically associated with said first and second toolrest position control switch members for selecting one of the other ofsaid last-mentioned switches for operation, and a centrifugal devicecarried by said driven shaft for operating the one of said selectedposition control switch members.

2. In combination, a driven shaft for moving a tool, an electricallyoperated power transmitter operatively connected to said shaft, a pairof electrical shaft position switches, one of said position switchesdetermining one position of rest of said shaft upon controlled cessationof operation of the power transmitter and the other of said positionswitches determining another position of rest of said shaft uponcontrolled cessation of operation of the power transmitter, acentrifugal device carried by said driven shaft for automaticallyoperating one or the other of said position members, a runningelectrical circuit including said transmitter, a control electricalcircuit connected with said running circuit and including said positionswitches, a main control switch included in both of said circuits, and amanual switch included in said control circuit, selective operation ofsaid manual switch determining operation of a predetermined positionswitch.

3. A control apparatus for an automatic reciprocatory tool, comprising adriven shaft connected to the tool for reciprocating the latter betweenextreme in and out positions, a solenoid operated stop and gotransmitter operatively connected to said shaft to drive it, and meansfor predetermining a position of rest of said tool in either its in orits out position upon cessation of operation of the transmitter, saidlatter means including a tool in switch and a tool out switch, both ofwhich are electrically associated with said transmitter, manuallyoperated means electrically associated with said, switches for selectingone or the other of the same for operation, and a centrifugal devicecarried by said driven shaft for operating the selected one of theaforesaid switches.

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